PSU for GPU

[Trophlin]

I've been looking at some GPU's GTX specs. Within the specs are listed "graphics card power" and "minimum system power requirement."

For example:
Graphics Card Power (W): 250 W
Minimum System Power Requirement (W): 600 W

I know you want to add up each individual hardware piece to find the total wattage for a PSU match. From everything I have found through searching is that you want to use the minimum system power requirement (600 W) then add each individual hardware power usage on top of that. If the graphics card power (250 W) is given why wouldn't you use this number if that is the power it uses?

 

[LZ_Xray]

What you really want for the GPU is power available on the +12V rail. 250w/12v is about 20.8A, so you want a power supply with significantly more than 21A available on the +12v rail since most of the power to other components of your machine is from that rail as well. 40A is about as close as I'd go, which would generally mean about a 500w PSU. On good PSUs the vast majority of the power is on the +12v.

Once you've taken into account the GPU and the CPU both overclocked, you've taken into account most of your power draw. Unless you have a silly amount of drives and fans, all the rest together won't amount to more than about 50w.

 

[dragonstongue]

he quote this number from a test machine people use crap PSU as do many system builders so they try to make sure all sides are covered usually enough watts to provide the required amps in a typical build you probably would see this used in. Most motherboards are `30-60w harddrives, case fans and such amount to maybe another 30w tops in vast majority of systems I would s `90w barebones before cpu-gpu is added most builds are sub 500w

 

[Armenius]

I've been looking at some GPU's GTX specs. Within the specs are listed "graphics card power" and "minimum system power requirement."

For example:
Graphics Card Power (W): 250 W
Minimum System Power Requirement (W): 600 W

I know you want to add up each individual hardware piece to find the total wattage for a PSU match. From everything I have found through searching is that you want to use the minimum system power requirement (600 W) then add each individual hardware power usage on top of that. If the graphics card power (250 W) is given why wouldn't you use this number if that is the power it uses?

The minimum power requirement reported on a GPU is taking an entire typical system into account. So that 600W requirement being reported is taking into account every other component in the PC.

Beyond that, it is also giving a buffer since you don't want your PSU running at 100% capacity 100% of the time. You can use an online tool to estimate peak system wattage based on the rest of your configuration. From there I would add 30% to get the wattage of the PSU you should buy/have if it doesn't give a recommendation. For example: if total system wattage is estimated to be 410W, then 410+(0.3*410)=533. In that case you should get at least a 550W PSU. The important thing to remember as mentioned earlier is to make sure the +12V rail has enough amperage to push all the components utilizing it.

 

[Skripka]

The minimum power requirement reported on a GPU is taking an entire typical system into account. So that 600W requirement being reported is taking into account every other component in the PC.

Beyond that, it is also giving a buffer since you don't want your PSU running at 100% capacity 100% of the time. You can use an online tool to estimate peak system wattage based on the rest of your configuration. From there I would add 30% to get the wattage of the PSU you should buy/have if it doesn't give a recommendation. For example: if total system wattage is estimated to be 410W, then 410+(0.3*410)=533. In that case you should get at least a 550W PSU. The important thing to remember as mentioned earlier is to make sure the +12V rail has enough amperage to push all the components utilizing it.

Any quality PSU can be run at 100% rated load fine. The wattage rating is a sustained load figure and not a peak load rating, for any quality PSU.

The PSU in my signature for example is rated at 750W. It has been tested to 900W+ draw by reviewers and still worked and kept putting out power within ATX specification. Running it at 750W rated load is nothing in comparison.

 

[dragonstongue]

this again. Just cause anything is built to do a certain redline factor say "750w" does not mean you should run it at a constant redline. The makers may build it to deliver X but in vast majority of cases did not build it to run in a fully loaded state constantly as you pointed out, that is a buffer zone ~80% is perfect for heat, efficiency etc. Just the same as a GPU is not meant to really be run in a full load state sure it can do it but it certainly wears out faster, and with the psu if it dies it can take out other parts even though it should not.

Buddy just had this happen with his psu started being a whore (HX750) with his system i7 950 radeon 6950 he does not overclock and cleans system properly every Friday evening its as also on a commercial battery backup anyways psu up and gave out took out both hard-drives and cooked channel A1 on his motherboard possibly more (Asus in process of fixing it)

Point is, Nvidia and such leave headroom cause many folks are not using quality power supplies that is the reality as much as most graphics adapters are not full blown discrete cards. It just a stupid idea to run something full out when it could can and does fry things, its your $ by all means. 80% is a nice figure leaves overhead for the 100% and much less likely to just conk out cause it got wore out from high loads.

 

[Skripka]

this again. Just cause anything is built to do a certain redline factor say "750w" does not mean you should run it at a constant redline. The makers may build it to deliver X but in vast majority of cases did not build it to run in a fully loaded state constantly as you pointed out, that is a buffer zone ~80% is perfect for heat, efficiency etc. Just the same as a GPU is not meant to really be run in a full load state sure it can do it but it certainly wears out faster, and with the psu if it dies it can take out other parts even though it should not.

Buddy just had this happen with his psu started being a whore (HX750) with his system i7 950 radeon 6950 he does not overclock and cleans system properly every Friday evening its as also on a commercial battery backup anyways psu up and gave out took out both hard-drives and cooked channel A1 on his motherboard possibly more (Asus in process of fixing it)

Point is, Nvidia and such leave headroom cause many folks are not using quality power supplies that is the reality as much as most graphics adapters are not full blown discrete cards. It just a stupid idea to run something full out when it could can and does fry things, its your $ by all means. 80% is a nice figure leaves overhead for the 100% and much less likely to just conk out cause it got wore out from high loads.

If a 750W PSU cannot properly power an i7-950 and a single 6950...then something was flawed with the unit...because he wasn't even running that unit at 60% capacity. Max draw 500W, and that presumes he was clocking the hell out of his CPU and was driving Delta 250CFM fans.

By your own flawed "this again" logic...his PSU should have been fine.


You have a lemon 1-in-a-100 product...you're going to get a lemon result regardless of how you go into it. Your pal had a lemon, unless you're intentionally misleading me or leaving a great deal out.

 

[cantoncobaltsssc]

I agree there was something wrong with that PSU. No way a 750w power supply was being pushed to the limits by i7 950 and 6950. I ran SLI 760's overclocked & i7 @ 4.4 ghz and drew only 600 watts running furmark on my HX 850.

 

[Supercharged_Z06]

Lots of folks think that as long as their system's load falls at or below their power supply's advertised rating that they are good to go. The thing is that many power supply manufacturers tend to do a rather poor job of actually honestly rating their supplies (big numbers = more sales), so while many may be able to temporarily hold a peak load at a given rating, they often can't pull the train so to speak in the long run. A good rule of thumb is to buy a supply that you intend to only load up to roughly 60-70% of its advertised max rated capacity. It will operate much more efficiently that way and as an added bonus, it will also run much cooler.

Don't trust what I say, go look at some power efficiency/performance curves from reputable manufacturers. They'll back up what I claim.

 

[Skripka]

Lots of folks think that as long as their system's load falls at or below their power supply's advertised rating that they are good to go. The thing is that many power supply manufacturers tend to do a rather poor job of actually honestly rating their supplies (big numbers = more sales), so while many may be able to temporarily hold a peak load at a given rating, they often can't pull the train so to speak in the long run. A good rule of thumb is to buy a supply that you intend to only load up to roughly 60-70% of its advertised max rated capacity. It will operate much more efficiently that way and as an added bonus, it will also run much cooler.

Don't trust what I say, go look at some power efficiency/performance curves from reputable manufacturers. They'll back up what I claim.

If you read PSU reviews...you would know that this statement is patently false.

 

[Trophlin]

The PSU I have is rated at a max 32A/384W/+12V. What would be a recommended GPU? This will be connected to a 1080p TV so no multiple monitors at a higher resolution. Although with 4K coming out it would be nice to future proof whatever I would purchase. I'm not against upgrading the PSU either if need be.

 

[Dangman]

The PSU I have is rated at a max 32A/384W/+12V. What would be a recommended GPU? This will be connected to a 1080p TV so no multiple monitors at a higher resolution. Although with 4K coming out it would be nice to future proof whatever I would purchase. I'm not against upgrading the PSU either if need be.

What PSU do you actually have?

 

[Trophlin]

What PSU do you actually have?

It's a CX430 v2.3

 

[Supercharged_Z06]

If you read PSU reviews...you would know that this statement is patently false.

And your source is?

Efficiency generally peaks anywhere from 50–75% load for most it not practically all power supplies out there. Go above that and efficiency drops and more heat is generated.

 

[Skripka]

And your source is?

Efficiency generally peaks anywhere from 50–75% load for most it not practically all power supplies out there. Go above that and efficiency drops and more heat is generated.

Read any PSU review on Johnny Guru. I mean any of them.

Quality PSUs don't have a 20% efficiency drop . They just don't these days. Most of the good power supplies (read Seasonic rebrands for example) only vary in efficiency 4% at most barring standby ultra-low power output modes....and those that vary at 5% fail their 80Plus cert.

Hell if you know anything about the 80+ standard, you'd know this...you don't even need to read PSU reviews to know this. Ofc the 80+ standard only checks at 20%, 50%, and 100% load. If a PSU actually meets the 80Plus categorization it has at a maximum a 4% efficiency delta.. Because that is the absolute maximum any of the 80Plus colors allow for the cert. Is it possible to design a PSU such that it has a 4% effiency variance at those 3 points and horrendous efficiency in all other output levels...sure...OTOH it is also *possible* that I might shit a 24k 99.9999% pure gold brick tonight on the Throne.

Do you want me to spoon feed you and show you every Seasonic review charting efficiency ever done? The "efficiency drop" at 70%+ load myth is just as much a fairy tail for quality PSUs as unicorns and the Easter Bunny. And that 4% variance is something you'll never lose any meaningful amount of money on. That is why the 80Plus categorization above Bronze is rather silly.

 

[Supercharged_Z06]

Whoa there Skripka...ease off the accelerator and take a breath or two.

When did I say that PSU's have a 20% efficiency drop? I merrily stated that a PSU performs optimally at between 50–75% of their maximum rated load. Are you arguing against this statement? If so, please indicate so.

The problem here is that not everyone buys "quality" brands - there are a lot of mediocre supplies in use out there as the almighty dollar does weigh in heavily into the purchasing equation and there are a lot more no-name brand units in use then there are "quality" ones.

No need to spoon feed me anything. I'm talking about power supplies in general, taking into account the fact that not everyone goes out and buys top tier, quality Seasonic PSU's when making a purchase.

A rule of thumb is something that can typically be safely applied across the board... Exactly what are you ranting on about?

 

[Skripka]

Whoa there Skripka...ease off the accelerator and take a breath or two.

When did I say that PSU's have a 20% efficiency drop? I merrily stated that a PSU performs optimally at between 50–75% of their maximum rated load. Are you arguing against this statement? If so, please indicate so.

The problem here is that not everyone buys "quality" brands - there are a lot of mediocre supplies in use out there as the almighty dollar does weigh in heavily into the purchasing equation and there are a lot more no-name brand units in use then there are "quality" ones.

No need to spoon feed me anything. I'm talking about power supplies in general, taking into account the fact that not everyone goes out and buys top tier, quality Seasonic PSU's when making a purchase.

A rule of thumb is something that can typically be safely applied across the board... Exactly what are you ranting on about?

Put it this way...you buy a $15 Hantol PSU with a concrete block in place of a PFC...you get exactly what you deserve. A PC that is on fire.


Because between quality PSUs...and fire crackers that blow up at 50% rated load... there isn't much in between. It is either one or the other. A PSU is either properly rated and puts out according to ATX spec and follows 80Plus (most makers slap an 80Plus sticker on) and is safe for your PC long term, or it isn't.

 

[455olds]

Whoa there Skripka...ease off the accelerator and take a breath or two.

When did I say that PSU's have a 20% efficiency drop? I merrily stated that a PSU performs optimally at between 50–75% of their maximum rated load. Are you arguing against this statement? If so, please indicate so.

The problem here is that not everyone buys "quality" brands - there are a lot of mediocre supplies in use out there as the almighty dollar does weigh in heavily into the purchasing equation and there are a lot more no-name brand units in use then there are "quality" ones.

No need to spoon feed me anything. I'm talking about power supplies in general, taking into account the fact that not everyone goes out and buys top tier, quality Seasonic PSU's when making a purchase.

A rule of thumb is something that can typically be safely applied across the board... Exactly what are you ranting on about?

He posted solid facts. Your concocting your own rule of thumb to buying a crappy power supply. Better advice would be to check reviews and stay away from "manufacturers tend to do a rather poor job of actually honestly rating their supplies" If a power supply can't run at full advertised wattage I wouldn't trust it to do 50% or 75%.
The power supply calculator recommends 90% and that is overkill. My computer pulls significantly less from the wall at full load then the power supply calculator came up with for wattage.
If the op is on a budget he is better off buying a quality power supply that is close to requirements he needs,then getting a higher rated less quality one for same price.

Trophlin
PSU for GPU
I've been looking at some GPU's GTX specs. Within the specs are listed "graphics card power" and "minimum system power requirement."

For example:
Graphics Card Power (W): 250 W
Minimum System Power Requirement (W): 600 W

I know you want to add up each individual hardware piece to find the total wattage for a PSU match. From everything I have found through searching is that you want to use the minimum system power requirement (600 W) then add each individual hardware power usage on top of that. If the graphics card power (250 W) is given why wouldn't you use this number if that is the power it uses?

I would use this power supply calculator and pick a good quality power supply. http://extreme.outervision.com/psucalculatorlite.jsp

 

[Supercharged_Z06]

He posted solid facts. Your concocting your own rule of thumb to buying a crappy power supply. Better advice would be to check reviews and stay away from "manufacturers tend to do a rather poor job of actually honestly rating their supplies" If a power supply can't run at full advertised wattage I wouldn't trust it to do 50% or 75%.

Get the wad out of your panties. This is an enthusiast site - most folks coming here are very likely going to dabble with overclocking their CPU/GPU or go out and upgrade their hardware on a regular basis. Getting a power supply and then loading it to 100% of its rating may work, but its pretty short sighted in that it will tend to run hotter and provide very little headroom for future upgrades and/or overclocking.

My rule of thumb wasn't intended as an excuse to go out and buy a crappy supply. Your words not mine. I was just sharing my own experience - I've been building PC's for 25+ years. I also encourage everyone to buy a quality supply from a reputable company that has been reviewed and proven sound. But it does also help to:
a) Run the supply as efficiently as possible.
b) Provide yourself with enough headroom for future upgrades / OCing

 

[Trophlin]

I would use this power supply calculator and pick a good quality power supply. http://extreme.outervision.com/psucalculatorlite.jsp

If i put everything in correct it looks like I can get by with a 760 (TI). Is this a respectable card for my needs or would it be worth it to upgrade the PSU and get a higher rated card?

 

[Supercharged_Z06]

If i put everything in correct it looks like I can get by with a 760 (TI). Is this a respectable card for my needs or would it be worth it to upgrade the PSU and get a higher rated card?

Typically you would select a GPU that is desired to match your needs/wants first and then consider the PSU that would be required to drive it. At least that's the approach most folks take.

You mentioned wanting to hook it to a 1080P TV, but then you also mentioned that with 4K coming that you would also like to future proof whatever you purchased. Well, to be honest, to effectively drive/game at 4K right now, you would need to consider a pair of Titans or 780Ti's. (That is if you don't want to significantly turn down/hobble all of the graphics eye candy in game settings.) There is a HUGE difference as far as graphic loads go when jumping from 1080p gaming to 4k gaming. (4K has approximately four times more resolution than 1080P). Yes, a 760Ti will most likely suit your needs if you are looking for a solid solution for 1080P gaming, but you can pretty much forget about using it for 4K gaming - there's just not enough oomph there. If you are really after a 4K gaming solution, I'd wait for Nvidia to release their big Maxwell offering later this year...

 

[Trophlin]

Typically you would select a GPU that is desired to match your needs/wants first and then consider the PSU that would be required to drive it. At least that's the approach most folks take.

You mentioned wanting to hook it to a 1080P TV, but then you also mentioned that with 4K coming that you would also like to future proof whatever you purchased. Well, to be honest, to effectively drive/game at 4K right now, you would need to consider a pair of Titans or 780Ti's. (That is if you don't want to significantly turn down/hobble all of the graphics eye candy in game settings.) There is a HUGE difference as far as graphic loads go when jumping from 1080p gaming to 4k gaming. (4K has approximately four times more resolution than 1080P). Yes, a 760Ti will most likely suit your needs if you are looking for a solid solution for 1080P gaming, but you can pretty much forget about using it for 4K gaming - there's just not enough oomph there. If you are really after a 4K gaming solution, I'd wait for Nvidia to release their big Maxwell offering later this year...

Well I built this with a budget HTHP in mind, hence the lower rated PSU. I'm not a big gamer but was thinking if I ever wanted to try it out to decide on a decent GPU. It seems more realistic to wait for better cards in the future for the greater demand needed for 4K. Would it be even a better choice to get a lower spec'd card for my needs? I am confused as what I should be looking at. I know the big fuss is about FPS and resolution. Being on a 1080p TV I'm not sure how that transpires.

 

[455olds]

Well I built this with a budget HTHP in mind, hence the lower rated PSU. I'm not a big gamer but was thinking if I ever wanted to try it out to decide on a decent GPU. It seems more realistic to wait for better cards in the future for the greater demand needed for 4K. Would it be even a better choice to get a lower spec'd card for my needs? I am confused at what I should be looking at. I know the big fuss is about FPS and resolution. Being on a 1080p TV I'm not sure how that transpires.

What are your system specs and what is your budget?

 

[tdowning]

Regarding putting a card into a HTPC with sub-400 watt PSU:

The podcast "This Week in Computer Hardware" from the twit.tv network Ryan Shrout recently ran a test where he bought the three cheapest PC's from the local Best Buy, and installed one of the new "Maxwell" based nVidia GPU's that don't require direct power supply connection, and found they were more than enough for 1080p gamaing.

 

[Supercharged_Z06]

Trophlin, as Tdowning just mentioned, if you aren't heavy into gaming, one of the best bang for the buck solutions right now as to a capable card for a HTPC would be the 750Ti card (2Gb version). It will handle light 1080p gaming quite well, won't break the bank (sub $200 card) and won't require you to mess with a new PSU. I've got one installed in my "kitchen" PC and have been very impressed with it - runs cool and seems to handle graphics tasks quite well. The 760Ti is a more capable card, but for you current needs, the 750Ti would probably work just fine and save you a bit of coin. It should easily hold you over till you decide to explore 4k options once big Maxwell arrives - which I predict won't arrive till late this year or even early next year.

 

[Trophlin]

What are your system specs and what is your budget?

CPU: Intel Core i5-4570 3.2GHz Quad-Core Processor
Motherboard: Gigabyte GA-B85M-D3H Micro ATX LGA1150 Motherboard
Memory: A-Data XPG V1.0 8GB (2 x 4GB) DDR3-1600 Memory
Storage: Samsung 840 Pro Series 128GB 2.5" Solid State Disk
Case: Silverstone GD05B-USB3.0 (Black) HTPC Case
Power Supply: Corsair Builder 430W 80+ Bronze Certified ATX Power Supply
Optical Drive: LG BH14NS40 Blu-Ray/DVD/CD Writer

I don't have a budget. Just best price/performance for my needs.

Regarding putting a card into a HTPC with sub-400 watt PSU:

The podcast "This Week in Computer Hardware" from the twit.tv network Ryan Shrout recently ran a test where he bought the three cheapest PC's from the local Best Buy, and installed one of the new "Maxwell" based nVidia GPU's that don't require direct power supply connection, and found they were more than enough for 1080p gamaing.

That's really good to know! I wonder what games he tested on?

Trophlin, as Tdowning just mentioned, if you aren't heavy into gaming, one of the best bang for the buck solutions right now as to a capable card for a HTPC would be the 750Ti card (2Gb version). It will handle light 1080p gaming quite well, won't break the bank (sub $200 card) and won't require you to mess with a new PSU. I've got one installed in my "kitchen" PC and have been very impressed with it - runs cool and seems to handle graphics tasks quite well. The 760Ti is a more capable card, but for you current needs, the 750Ti would probably work just fine and save you a bit of coin. It should easily hold you over till you decide to explore 4k options once big Maxwell arrives - which I predict won't arrive till late this year or even early next year.

I was looking at the 750TI and comparing it to the 760. I guess the question would be is it worth the extra ~$80 ($150 vs $230)? I could always buy used but am hesitant doing that with electronics.

 

[Supercharged_Z06]

Everything is going to be pretty much playable with a 750Ti, while the 760 will give you roughly 50% more performance (FPS) on average in most games, put will produced a lot more heat and suck more power doing so. Go look at some comparison reviews like this one and then decide for yourself based on what you feel your needs are: http://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_750_Ti/

If it were me, I'd go with the 750Ti, especially since it's going into an HTPC and gaming is not going to be your prime use for the card.

 

[455olds]

CPU: Intel Core i5-4570 3.2GHz Quad-Core Processor
Motherboard: Gigabyte GA-B85M-D3H Micro ATX LGA1150 Motherboard
Memory: A-Data XPG V1.0 8GB (2 x 4GB) DDR3-1600 Memory
Storage: Samsung 840 Pro Series 128GB 2.5" Solid State Disk
Case: Silverstone GD05B-USB3.0 (Black) HTPC Case
Power Supply: Corsair Builder 430W 80+ Bronze Certified ATX Power Supply
Optical Drive: LG BH14NS40 Blu-Ray/DVD/CD Writer

I don't have a budget. Just best price/performance for my needs.



That's really good to know! I wonder what games he tested on?



I was looking at the 750TI and comparing it to the 760. I guess the question would be is it worth the extra ~$80 ($150 vs $230)? I could always buy used but am hesitant doing that with electronics.

I would consider this R9 270. http://www.newegg.com/Product/Product.aspx?Item=N82E16814150702
Its about $30 more than the 750 ti but should be a noticeable difference in performance with still keeping low power consumption. It also has a lifetime warranty.
This review shows both cards total system power draw under load running a benchmark. http://www.bit-tech.net/hardware/graphics/2014/02/18/nvidia-geforce-gtx-750-ti-review/10

This is cherry picking but here is where you would notice a difference in performance. 750ti at 22 min fps and 270 at 32 min fps. http://www.bit-tech.net/hardware/graphics/2014/02/18/nvidia-geforce-gtx-750-ti-review/5

 

[Trophlin]

Everything is going to be pretty much playable with a 750Ti, while the 760 will give you roughly 50% more performance (FPS) on average in most games, put will produced a lot more heat and suck more power doing so. Go look at some comparison reviews like this one and then decide for yourself based on what you feel your needs are: http://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_750_Ti/

If it were me, I'd go with the 750Ti, especially since it's going into an HTPC and gaming is not going to be your prime use for the card.

Good point! This looks like it would be a great option.

I would consider this R9 270. http://www.newegg.com/Product/Product.aspx?Item=N82E16814150702
Its about $30 more than the 750 ti but should be a noticeable difference in performance with still keeping low power consumption. It also has a lifetime warranty.
This review shows both cards total system power draw under load running a benchmark. http://www.bit-tech.net/hardware/graphics/2014/02/18/nvidia-geforce-gtx-750-ti-review/10

This is cherry picking but here is where you would notice a difference in performance. 750ti at 22 min fps and 270 at 32 min fps. http://www.bit-tech.net/hardware/graphics/2014/02/18/nvidia-geforce-gtx-750-ti-review/5

Seeing how much power these cards pull vs what they are listed at concerns me. My base system power usage without the GPU is estimated at 188W, granted I don't know how much would be on the +12V rail.

Intel Core i5-4570 3.2GHz Quad-Core Processor 10W - 84W
Gigabyte GA-B85M-D3H Micro ATX LGA1150 Motherboard 15W - 60W
A-Data XPG V1.0 8GB (2 x 4GB) DDR3-1600 Memory 9W - 9W
Seagate Momentus 5400.6 160GB 2.5" 5400RPM Internal Hard Drive 3W - 15W
Samsung 840 Pro Series 128GB 2.5" Solid State Disk 1W - 5W
Silverstone AP122 42.6 CFM 120mm Fan 1W - 5W
Silverstone AP122 42.6 CFM 120mm Fan 1W - 5W
Silverstone AP122 42.6 CFM 120mm Fan 1W - 5W
Total: 41W - 188W

For example the GTX 760 is listed at 170W while the chart in the link you provided is showing 292W. As long as I am under 384W on the +12V rail I should be good along with whatever headroom is needed. The 270 looks good especially for the price.